Stargardt Disease 4
A number sign (#) is used with this entry because Stargardt disease-4 (STGD4) is caused by heterozygous mutation in the prominin-1 gene (PROM1; 604365).
For a general phenotypic description and a discussion of genetic heterogeneity of Stargardt disease, see STGD1 (248200).
DescriptionStargardt disease is the most common hereditary macular dystrophy and is characterized by decreased central vision, atrophy of the macula and underlying retinal pigment epithelium, and frequent presence of prominent flecks in the posterior pole of the retina. STGD is most commonly inherited as an autosomal recessive trait (see 248200), but STGD4 is inherited as an autosomal domiant trait (summary by Kniazeva et al., 1999).
Clinical FeaturesKniazeva et al. (1999) studied 26 members of a 3-generation Caribbean kindred with an autosomal dominant Stargardt-like phenotype. Twelve living individuals in 2 generations were thought to be affected on the basis of decreased visual acuity and macular atrophy. Fluorescein angiography performed in 4 affected subjects demonstrated the characteristic dark-choroid pattern of STGD. Three patients showed typical STGD flavimaculatus flecks. Two affected subjects studied by electroretinography showed normal rod photoreceptor response and mildly decreased cone photoreceptor response in one case and very mildly reduced rod response and mildly reduced cone response in the other case.
MappingKniazeva et al. (1999) performed a genomewide search in a 3-generation Caribbean family segregating an autosomal dominant Stargardt-like phenotype and demonstrated linkage to chromosome 4p, with a maximum lod score of 5.12 at a recombination fraction of 0.0 for marker D4S403. Analysis of extended haplotypes localized the disease gene to an interval of approximately 12 cM between loci D4S1582 and D4S2397.
Molecular GeneticsIn affected members of a 4-generation Caribbean family with Stargardt disease, previously reported by Kniazeva et al. (1999), Yang et al. (2008) identified heterozygosity for a missense mutation in the PROM1 gene (604365.0003). (The citation for this family was erroneous in the article published by Yang et al., 2008 (Zhang, 2009).) Yang et al. (2008) identified the same mutation in a family with retinal macular dystrophy (MCDR2; 608051) and in a family with cone-rod dystrophy (CORD12; 612657); the mutation was not found in 400 matched controls.